AU756141B2 - High sensitivity particle detection - Google Patents
High sensitivity particle detection Download PDFInfo
- Publication number
- AU756141B2 AU756141B2 AU94504/98A AU9450498A AU756141B2 AU 756141 B2 AU756141 B2 AU 756141B2 AU 94504/98 A AU94504/98 A AU 94504/98A AU 9450498 A AU9450498 A AU 9450498A AU 756141 B2 AU756141 B2 AU 756141B2
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- AU
- Australia
- Prior art keywords
- radiation
- particles
- detecting
- predetermined
- detector
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B17/00—Fire alarms; Alarms responsive to explosion
- G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
- G08B17/103—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device
- G08B17/107—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using a light emitting and receiving device for detecting light-scattering due to smoke
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B17/00—Fire alarms; Alarms responsive to explosion
- G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
- G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
- G08B17/113—Constructional details
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- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Fire-Detection Mechanisms (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
A smoke detector is disclosed in which smoke particles are detected by the collection and detection of blue light and infra-red radiation which are emitted into a predetermined path through a scattering volume where the particles may be present. The scattered blue light and the scattered infra-red radiation are collected by an ellipsoidal mirror and focussed onto a suitable detector and then compared to produce an output which indicates either that the detected particles are smoke particles or that they are not smoke particles. The radiation collected by the mirror has been scattered through angles substantially less than 45° and preferably between about 10° and 35°.
Description
P:\OPER\GCP\945o.98 -sp1 227.doc-48l 1)2 -1- HIGH SENSITIVITY PARTICLE DETECTION The invention relates to a particle detector for detecting particles of sizes of less than one micron, comprising radiation emitting means for emitting radiation at two different wavelengths along a predetermined path through a scattering volume, the radiation at one of the wavelengths lying between about 400nm and about 500nm, and radiation detection means for receiving and detecting the radiation scattered from the scattering volume by the presence of particles at a predetermined forward scattering angle of less than 450 to the predetermined path of radiation.
oooo o" :The invention also relates to a particle detecting method for detecting particles of sizes of less than one micron, comprising the steps of emitting radiation at two different wavelengths along a predetermined path through a scattering volume, one wavelength lying between about 400nm and 500nm, and receiving and detecting the radiation scattered .00 15 from the scattering volume by the presence of particles at a predetermined forward scattering angle of less than 450 to the predetermined path of radiation.
Such a detector and such a method are shown, for example, in GOODMAN D.S.: "METHOD FOR LOCALISING LIGHT-SCATTERED PARTICLES"; IBM S 20 TECHNICAL DISCLOSURE BULLETIN vol. 27, no. 5, October 1984, page 3164 XP 002066860, and in WO-A-89 09392.
The invention aims to improve the sensitivity of such a detector and such a method so that the detector and the method are better able to discriminate against particles of a type which are not intended to be detected.
According to the invention, there is provided a particle detector for detecting particles of sizes of less than one micron, comprising radiation emitting means for emitting radiation at two different wavelengths along a predetermined path through a scattering volume, the radiation at one of the wavelengths lying between 400nm and 500nm, and radiation detection means for receiving and detecting the radiation scattered from the scattering P:OPER\GCP\K9450498 r-p] 227.dmo8JI/1/02 -2volume by the presence of particles at a predetermined forward scattering angle of less than 450 to the predetermined path of radiation, in which the radiation of the other wavelength is infra-red radiation, and including output means for comparing outputs from the detecting means respectively corresponding to the received and detected radiation between 400nm and 500nm and the received and detected infra-red radiation whereby to produce a warning signal when the comparison indicates that the particles are of a predetermined type but not when the comparison indicates otherwise.
The present invention also provides a particle detecting method for detecting particles of 10 sizes of less than one micron, comprising the steps of emitting radiation at two different wavelengths along a predetermined path through a scattering volume, one wavelength lying between 400nm and 500nm, and receiving and detecting the radiation scattered from the scattering volume by the presence of particles at a predetermined forward scattering angle of less than 450 to the predetermined path of radiation, in which the other wavelength is a wavelength of infra-red radiation, and including the step of comparing two outputs respectively corresponding to the received and detected radiation between 400nm and about 500nm and the received and detected infra-red radiation whereby to produce a S0:" warning signal when the comparison indicates that the particles are of a predetermined So o •type but not when the comparison indicates otherwise.
High sensitivity particle detection apparatus embodying the invention, and methods according to the invention, will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a schematic diagram of apparatus for explaining the operation of apparatus embodying the invention which is shown in Figure Figures 2, 3 and 4 are graphs for explaining the operation of the apparatus shown in Figure 1; Figure 5 is a schematic diagram of apparatus embodying the invention; and PA\OPERMGC94504-98 -p 227.do4J8I 1(12 -2A- Figures 6 and 7 are graphs for explaining the operation of the apparatus embodying the invention shown in Figure The apparatus and methods to be described are for detecting smoke in air using light scattering techniques, although it will be appreciated that other particles can be detected using the same apparatus and methods. The apparatus and methods aim to detect the presence of smoke particles at smoke densities **o WO 99/19852 PCT/GB98/03079 3 at least as low as 0.2% per metre. The primary use of such apparatus is for detecting incipient fires.
The apparatus 1 (Figure 1) comprises a radiation source 3 emitting radiation along a path 5. Radiation 7 passes through a volume 9 towards a beam dump 11. An ellipsoidal mirror 13 is positioned for collecting radiation scattered by the presence of smoke particles in the volume 9 (within a predetermined range of forward scattering angles to be discussed below) and focussing such radiation on a silicon photodiode It will be appreciated that the collection means for the scattered radiation need not be an ellipsoidal mirror 13 but may be any suitable collection means. Additionally, it will also be appreciated that any suitable detector means may be used and the detector need not be silicon photodiode In use, radiation 7 from the radiation source 3 is emitted along the path 5 through the scattering volume 9. The presence of any smoke particles in the scattering volume 9 will cause the radiation 7 to be scattered through a predetermined range of angles. The ellipsoidal mirror 13 is positioned such that any light scattered at forward scattering angles of less than 450, and more particularly at scattering WO 99/19852 PCT/GB98/03079 4 angles between about 100 and 350 will be collected by the ellipsoidal mirror 13. The ellipsoidal mirror 13 focuses the light scattered at these angles from the scattering volume in all planes perpendicular to the incident radiation direction on to the silicon photodiode 15. This arrangement maximises the radiation incident on the photodiode 15. The signal produced by the silicon photodiode 15 may be used to trigger a suitable alarm system and/or a fire extinguishing system.
Any radiation which is not scattered will be incident on and be trapped substantially by the beam dump 11 and no corresponding signal will be produced by the silicon photodiode The radiation source 3 emits radiation 7 at relatively short wavelengths between about 400nm and 500nm, that is, blue visible light; preferably, the radiation source 3 is an LED producing radiation at 470 nm wavelength. It is found that the use of this relatively short wavelength, combined with the use of relatively small forward scattering angles, produces increased sensitivity of particle detection, at least for smoke particles This is explained in more detail with reference to Figures 2 to 4.
Curve A in Figure 2 shows the output of the detector 15 for WO 99/19852 PCT/GB98/03079 different degrees of smoke obscuration expressed as a percentage of light obscured per metre. Curves B, C, D and E show the corresponding detector outputs at the same scattering angle but for different (longer) radiation wavelengths.
Curve B shows the detector output where the radiation is in the green part of the spectrum. Curve C shows the detector output where the radiation is in the red part of the spectrum.
Curve D shows the detector output when the radiation is in the infra-red part of the spectrum and of the order of 880 nm.
Finally, curve E shows the detector output when the radiation is in the infra-red part of the spectrum and of the order of 950 nm. In each case, the range of forward scattering angles is the same (between about 10' and 350). The smoke for the tests illustrated was produced by smouldering cotton.
Figure 2 clearly shows the increased detector output, and thus the increased sensitivity of detection, which is obtained by using a radiation source producing blue visible light of the order of 470 nm. Figure 2 shows how detectable signals can be produced from the photodiode 15 at smoke densities as low as 0.2% per metre. Radiation at the other wavelengths (curves B, C, D and E) produces significantly lower outputs.
Shorter wavelength light also has the advantage that it has a lower reflectivity from typical matt black surfaces. By WO 99/19852 PCT/GB98/03079 6 suitable design of the detecting apparatus, therefore, the output from the photodiode 15 due to background scattered light signals (primarily signals reflected from internal surfaces of the apparatus and not due to smoke) can be made very small and significantly less than when light of longer wavelengths is used.
Figure 3 plots the calculated scattering gain for a particle size distribution typical of smoke against the forward scattering angle using light at different wavelengths.
Scattering gain is the amount of light scattered into a unit solid angle as a fraction of the light falling on an individual particle. Curve A corresponds to blue visible light, curve B to green visible light, curve C to red visible light, curve D to infra-red radiation of the order of 880 nm, ahd curve E to infra-red radiation of 950 nm. Figure 3 shows how the use of blue visible light (curve A) produce significantly more scattering gain than radiation at the other wavelengths (curves B to E) at scattering angles up to about 1550, although the increase in scattering gain is much more pronounced at scattering angles less than 450 Curves A in Figures 2 and 3 therefore show how the combination of the use of blue visible light (radiation between 400 and 500nm) and the use of low scattering angles (between about 100 WO 99/19852 PCT/GB98/03079 7 and 350) produces a significant increase in sensitivity.
Smoke detectors may be susceptible to false alarms in the presence of larger aerosol particles such as condensed water mist or dust. Figure 4 corresponds to Figure 3 except that the particles used are particles having a size distribution typical of condensed water mist, and calculations were carried out for only two wavelengths: blue visible light at 450 nm (curve and infra-red radiation at 950 nm (curve E) Curves A and E in Figure 4 show that the scattering gain is substantially the same at both the wavelengths tested, at least for scattering angles between about 150 and 300. A comparison of Figures 3 and 4 therefore shows that the ratio (signal to noise ratio) between the output of the photodiode in response to smoke particles and the corresponding output fbr "nuisance" aerosols, such as water mist particles, will be higher when blue light is used than when radiation at the other wavelengths is used.
Figure 5 shows a modified arrangement of Figure 1 which uses the principle illustrated by comparing Figures 3 and 4. In Figure 5 items corresponding to items in Figure 1 are similarly referenced. In Figure 5, the source 3 of Figure 1 is supplemented by a source 3A. Source 3 produces blue light, as before, in the range 400 to 500 nm. Source 3A produces WO 99/19852 PCT/GB98/03079 8 infra-red radiation at about 880 nm and may (like source 3) be an LED. The radiation emitted by both sources is passed via a beam splitter 17 and thence through the volume 9.
As before, radiation forward-scattered (at the appropriate angles) by obscuration in the volume 9 is collected by the ellipsoidal mirror 13 and focussed an detector 15. As before, detector 15 is a silicon photodiode. Such a detector is sensitive to blue light and also infra-red radiation at about 880nm. A control system indicated generally at 19 and enables the detector 15 to produce separate outputs on lines 21 and 23 corresponding respectively to the scattered blue light and the scattered infra-red radiation as received by the detector. The control system 19,20 may take any suitable form. For example, it may arrange to pulse the sources 3 and 3A alternately and to switch the detector output synchronously between the lines 21 and 23. Instead, the sources 3 and 3A can be energised separately at different frequencies and separate narrow band or lock-in amplifiers can be used for responding to the output from the detector and for respectively energising the lines 21 and 23. The outputs of the detector 15 on lines 21 and 23 are processed by a comparison unit Figures 6 and 7 illustrate the operation of the arrangement of WO 99/19852 PCT/GB98/03079 9 Figure In Figures 6 and 7, the horizontal axis represents time, the left hand vertical axis represents visible obscuration expressed as a percentage of light obscured per metre, and the right hand vertical axis represents the output of the detector in Figure 5. The left and right hand axis are to a logarithmic scale.
Figure 6 shows results obtained when obscuration is caused by smoke (in this case, grey smoke produced by smouldering cotton), the smoke being released for 5s at 100s and then for 100s between 200 and 300s. In Figure 7, the obscuration is caused by a non-smoke source, in this case by a hairspray aerosol. A one second spray is released at 100s and a spray at 200s.
In Figure 6, curve I plots the obscuration. Curve II plots the output of the detector 15 in response to the blue light emitted by the source 3. Curve III plots the output of detector 15 in response to the infra-red radiation emitted by source 3A. It will be seen that the detector output in response to the scattered infra-red radiation (Curve III) is much less than the detector output in response to the scattered blue light (curve II). Curve IV shows the ratio of P:\OPER\GCP\945(4-98 respl 227.doc4)8/ 1/12 the detector output when the emitted radiation is blue light (curve I I) to the output when the emitted radiation is infra-red (curve II The ratio is significantly greater than one.
In Figure 7, the curves I, I I, I I I and IV have the same identities as in Figure 6. It will be noted that the ratio shown by curve IV is significantly less than one.
The unit 23 is therefore arranged to measure the ratio of the output of detector 15 to the output of detector 15A. If this ratio is more than one, obscuration by smoke is signalled.
S* If the ratio is less than one, smoke obscuration is not signalled.
The infra-red radiation used in the embodiment of Figure 5 does not need to be at 880nm.
o The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common 15 general knowledge in Australia.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps 20 but not the exclusion of any other integer or step or group of integers or steps.
Claims (14)
1. A particle detector for detecting particles of sizes of less than one micron, comprising radiation emitting means for emitting radiation at two different wavelengths along a predetermined path through a scattering volume, the radiation at one of the wavelengths lying between 400nm and 500nm, and radiation detection means for receiving and detecting the radiation scattered from the scattering volume by the presence of particles at a predetermined forward scattering angle of less than 45° to the predetermined path of radiation, in which the radiation of the other wavelength is infra-red radiation, and 10 including output means for comparing outputs from the detecting means respectively 0: corresponding to the received and detected radiation between 400nm and 500nm and the received and detected infra-red radiation whereby to produce a warning signal when the comparison indicates that the particles are of a predetermined type but not when the comparison indicates otherwise.
2. A detector according to claim 1, in which the particles are smoke particles.
3. A detector according to claim 1 or 2, in which the detection means is a photodiode. .20 4. A detector according to any preceding claim, in which the output means measures the ratio between the two said outputs. A detector according to any preceding claim, in which each radiation emitting means is an LED.
6. A detector according to any preceding claim, in which the predetermined scattering angle lies in a range between about 10° and
7. A detector according to any preceding claim, including collecting and focussing means for collecting the scattered radiation and focussing it on the detection means. P:AOPER\GCPR9454)-98 rsplI 227doS)8/I I/I2 -12-
8. A detector according to claim 7, in which the collecting and focussing means is an ellipsoidal mirror.
9. A detector according to any preceding claim, including beam dump means positioned in the predetermined path and further from the radiation emitting means than the scattering volume. A detector according to any preceding claim, in which the radiation emitting means simultaneously emits radiation at the two different wavelengths along the predetermined 10 path through the scattering volume. ooo*
11. A particle detecting method for detecting particles of sizes of less than one micron, comprising the steps of emitting radiation at two different wavelengths along a predetermined path through a scattering volume, one wavelength lying between 400nm 15 and 500nm, and receiving and detecting the radiation scattered from the scattering volume by the presence of particles at a predetermined forward scattering angle of less than 450 to the predetermined path of radiation, in which the other wavelength is a wavelength of S-infra-red radiation, and including the step of comparing two outputs respectively .corresponding to the received and detected radiation between 400nm and about 500nm and the received and detected infra-red radiation whereby to produce a warning signal when the comparison indicates that the particles are of a predetermined type but not when the comparison indicates otherwise.
12. A method according to claim 11, in which the particles are smoke particles.
13. A method according to claim 11 or 12, in which the comparison step comprises the step of measuring the ratio between the compared outputs.
14. A method according to any one claims 11 to 13, in which the predetermined S scattering angle lies in a range between about 10* and 350 P\OPER\GCP\94504-98 respl 227.doc-08/ 1/02 13 A method according to any one of claims 11 to 14, including the step of collecting and focussing the scattered radiation.
16. A method according to any one of claims 11 to 15, in which the step of emitting radiation at two different wavelengths along the predetermined path through the scattering volume comprises the step of simultaneously so emitting the radiation at the two different wavelengths.
17. A particle detector for detecting particles all sizes less than one micron 10 substantially as hereinbefore described with reference to the accompanying drawings.
18. A particle detecting method for detecting particles of sizes less than one micron substantially as hereinbefore described with reference to the accompanying drawings. DATED this 8th day of November, 2002 see*: Kidde Fire Protection Limited by DAVIES COLLISON CAVE Patent Attorneys for the Applicant
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9721861 | 1997-10-15 | ||
| GBGB9721861.4A GB9721861D0 (en) | 1997-10-15 | 1997-10-15 | High sensitivity particle detection |
| PCT/GB1998/003079 WO1999019852A1 (en) | 1997-10-15 | 1998-10-13 | High sensitivity particle detection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU9450498A AU9450498A (en) | 1999-05-03 |
| AU756141B2 true AU756141B2 (en) | 2003-01-02 |
Family
ID=10820603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU94504/98A Ceased AU756141B2 (en) | 1997-10-15 | 1998-10-13 | High sensitivity particle detection |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US6377345B1 (en) |
| EP (1) | EP1023709B1 (en) |
| JP (1) | JP2001520390A (en) |
| AT (1) | ATE220233T1 (en) |
| AU (1) | AU756141B2 (en) |
| DE (1) | DE69806404T2 (en) |
| DK (1) | DK1023709T3 (en) |
| ES (1) | ES2175790T3 (en) |
| GB (2) | GB9721861D0 (en) |
| WO (1) | WO1999019852A1 (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| PT1103937E (en) * | 1999-11-19 | 2005-09-30 | Siemens Building Tech Ag | FIRE DETECTOR |
| GB2379977B (en) * | 2001-09-25 | 2005-04-06 | Kidde Plc | High sensitivity particle detection |
| GB2389176C (en) | 2002-05-27 | 2011-07-27 | Kidde Ip Holdings Ltd | Smoke detector |
| US7564365B2 (en) * | 2002-08-23 | 2009-07-21 | Ge Security, Inc. | Smoke detector and method of detecting smoke |
| DE60325254D1 (en) | 2002-08-23 | 2009-01-22 | Gen Electric | MMUNER ALARM SIGNAL GENERATION SMOKE DETECTOR |
| US7794663B2 (en) * | 2004-02-19 | 2010-09-14 | Axcelis Technologies, Inc. | Method and system for detection of solid materials in a plasma using an electromagnetic circuit |
| US7148485B2 (en) * | 2004-05-28 | 2006-12-12 | Hewlett-Packard Development Company, L.P. | Low-energy charged particle detector |
| TW200821995A (en) * | 2006-09-07 | 2008-05-16 | Siemens Schweiz Ag | Improvement(s) related to particle monitors and method(s) therefor |
| DE102007045018B4 (en) * | 2007-09-20 | 2011-02-17 | Perkinelmer Optoelectronics Gmbh & Co.Kg | Radiation guide device for a detector, scattered radiation detector |
| US8085157B2 (en) | 2007-10-24 | 2011-12-27 | Honeywell International Inc. | Smoke detectors |
| DE102011119431C5 (en) | 2011-11-25 | 2018-07-19 | Apparatebau Gauting Gmbh | Stray radiation fire detector and method for automatically detecting a fire situation |
| EP2908298B1 (en) * | 2014-02-13 | 2018-04-18 | Siemens Schweiz AG | Smoke detector based on the scattered light principle with a two-colour light emitting diode with differently sized LED chips |
| GB2531495B (en) | 2014-06-16 | 2017-04-12 | Apollo Fire Detectors Ltd | Smoke detector |
| WO2017104533A1 (en) * | 2015-12-14 | 2017-06-22 | 三菱電機株式会社 | Minute object detection device |
| ES2894676T3 (en) | 2016-08-04 | 2022-02-15 | Carrier Corp | Smoke detector |
| US11067784B2 (en) * | 2017-05-01 | 2021-07-20 | Bae Systems Information And Electronic Systems Integration Inc. | System and techniques for detecting fluorescing particles on a target |
| US10466176B2 (en) * | 2017-05-01 | 2019-11-05 | Bae Systems Information And Electronic Systems Integration Inc. | System and method for detecting contaminants on a circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1989009392A1 (en) * | 1988-03-30 | 1989-10-05 | Martin Terence Cole | Fluid pollution monitor |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH546989A (en) * | 1972-12-06 | 1974-03-15 | Cerberus Ag | METHOD AND DEVICE FOR FIRE NOTIFICATION. |
| GB1434787A (en) | 1973-04-04 | 1976-05-05 | Shaw Mfg Ltd | Hinges |
| FR2357888A1 (en) * | 1976-04-01 | 1978-02-03 | Cerberus Ag | SMOKE DETECTOR |
| CH592933A5 (en) * | 1976-04-05 | 1977-11-15 | Cerberus Ag | |
| US4226533A (en) * | 1978-09-11 | 1980-10-07 | General Electric Company | Optical particle detector |
| US4221485A (en) * | 1979-06-04 | 1980-09-09 | Honeywell Inc. | Optical smoke detector |
| DE3175819D1 (en) * | 1980-12-18 | 1987-02-12 | Cerberus Ag | Smoke detector according to the radiation extinction principle |
| US5416580A (en) * | 1993-07-07 | 1995-05-16 | General Signal Corporation | Methods and apparatus for determining small particle size distribution utilizing multiple light beams |
| GB2319604A (en) * | 1996-11-25 | 1998-05-27 | Kidde Fire Protection Ltd | Smoke and particle detector |
| JPH1123458A (en) | 1997-05-08 | 1999-01-29 | Nittan Co Ltd | Smoke sensor and monitoring control system |
-
1997
- 1997-10-15 GB GBGB9721861.4A patent/GB9721861D0/en active Pending
-
1998
- 1998-10-12 GB GB9822057A patent/GB2330410B/en not_active Expired - Lifetime
- 1998-10-13 US US09/446,968 patent/US6377345B1/en not_active Expired - Lifetime
- 1998-10-13 DK DK98947664T patent/DK1023709T3/en active
- 1998-10-13 AT AT98947664T patent/ATE220233T1/en not_active IP Right Cessation
- 1998-10-13 WO PCT/GB1998/003079 patent/WO1999019852A1/en active IP Right Grant
- 1998-10-13 JP JP2000516331A patent/JP2001520390A/en active Pending
- 1998-10-13 ES ES98947664T patent/ES2175790T3/en not_active Expired - Lifetime
- 1998-10-13 DE DE69806404T patent/DE69806404T2/en not_active Expired - Lifetime
- 1998-10-13 EP EP98947664A patent/EP1023709B1/en not_active Expired - Lifetime
- 1998-10-13 AU AU94504/98A patent/AU756141B2/en not_active Ceased
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1989009392A1 (en) * | 1988-03-30 | 1989-10-05 | Martin Terence Cole | Fluid pollution monitor |
Non-Patent Citations (1)
| Title |
|---|
| GOODMAN D.S."METHOD OF LOCALIZING LIGHT SCATTERED PARTICLES" IBM TECHNICAL DISCLOSURE BULLETIN VOL.27 NO.5, OCT 84 * |
Also Published As
| Publication number | Publication date |
|---|---|
| DE69806404T2 (en) | 2002-11-07 |
| EP1023709B1 (en) | 2002-07-03 |
| AU9450498A (en) | 1999-05-03 |
| GB9721861D0 (en) | 1997-12-17 |
| DE69806404D1 (en) | 2002-08-08 |
| ES2175790T3 (en) | 2002-11-16 |
| ATE220233T1 (en) | 2002-07-15 |
| WO1999019852A1 (en) | 1999-04-22 |
| JP2001520390A (en) | 2001-10-30 |
| DK1023709T3 (en) | 2002-07-22 |
| EP1023709A1 (en) | 2000-08-02 |
| GB2330410A (en) | 1999-04-21 |
| GB9822057D0 (en) | 1998-12-02 |
| GB2330410B (en) | 2002-03-06 |
| US6377345B1 (en) | 2002-04-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PC1 | Assignment before grant (sect. 113) |
Owner name: KIDDE FIRE PROTECTION SERVICES LIMITED Free format text: THE FORMER OWNER WAS: KIDDE FIRE PROTECTION LIMITED |
|
| FGA | Letters patent sealed or granted (standard patent) | ||
| PC1 | Assignment before grant (sect. 113) |
Owner name: KIDDE IP HOLDINGS LIMITED Free format text: THE FORMER OWNER WAS: KIDDE FIRE PROTECTION SERVICES LIMITED |